关键词: 日本沼虾（Macrobrachium nipponense）, 线粒体, 遗传差异

Abstract: Macrobrachium nipponense samples from five different populations including Qiantang River （QT）, Wuyi （WY）, Gaotanghu （GT）, Zhaoqing （ZQ） and Nanning （NN） were collected in the experiment, and the mitochondrial COI gene of each population was sequenced and analyzed to understand the genetic differences among populations. The results showed that in the COI gene sequence of Macrobrachium nipponense, there were 420 conserved sites, 222 mutated sites, 123 reduced information sites, and 27 base deletion or insertion sites, with an average conversion to inversion ratio of 2.78. The content of （A+T） in the COI gene sequence was significantly higher than that of （G+C）, and the base composition exhibited significant AT bias. 65 haplotypes were defined in 67 individuals, and haplotypes from NN and QT populations formed two main branches. The phylogenetic tree and cluster tree constructed based on genetic distance showed that the genetic distance between QT population and GT population was relatively close, the genetic distance was relatively far compared with ZQ population and NN population, and the genetic distance between WY population and QT population and GT population was relatively small. The research results could provide a molecular biological basis for the rational development and utilization of Macrobracium germplasm resources.

Key words: Macrobrachium nipponense, mitochondrial, genetic differences